/* Return the public key algorithm number if S_KEY is a DSA style key.
If it is not a DSA style key, return 0. */
int
agent_is_dsa_key (gcry_sexp_t s_key)
{
int result;
gcry_sexp_t list;
char algoname[6];
if (!s_key)
return 0;
if (key_parms_from_sexp (s_key, &list, algoname, sizeof algoname, NULL, 0))
return 0; /* Error - assume it is not an DSA key. */
if (!strcmp (algoname, "dsa"))
result = GCRY_PK_DSA;
else if (!strcmp (algoname, "ecc"))
{
if (is_eddsa (list))
result = 0;
else
result = GCRY_PK_ECDSA;
}
else if (!strcmp (algoname, "ecdsa"))
result = GCRY_PK_ECDSA;
else
result = 0;
gcry_sexp_release (list);
return result;
}
/* Return true if S_KEY is an EdDSA key as used with curve Ed25519. */
int
agent_is_eddsa_key (gcry_sexp_t s_key)
{
int result;
gcry_sexp_t list;
char algoname[6];
if (!s_key)
return 0;
if (key_parms_from_sexp (s_key, &list, algoname, sizeof algoname, NULL, 0))
return 0; /* Error - assume it is not an EdDSA key. */
if (!strcmp (algoname, "ecc") && is_eddsa (list))
result = 1;
else if (!strcmp (algoname, "eddsa")) /* backward compatibility. */
result = 1;
else
result = 0;
gcry_sexp_release (list);
return result;
}
/* Return the Secure Shell type fingerprint for KEY using digest ALGO.
The length of the fingerprint is returned at R_LEN and the
fingerprint itself at R_FPR. In case of a error code is returned
and NULL stored at R_FPR. */
static gpg_error_t
get_fingerprint (gcry_sexp_t key, int algo,
void **r_fpr, size_t *r_len, int as_string)
{
gpg_error_t err;
gcry_sexp_t list = NULL;
gcry_sexp_t l2 = NULL;
const char *s;
char *name = NULL;
int idx;
const char *elems;
gcry_md_hd_t md = NULL;
int blobmode = 0;
*r_fpr = NULL;
*r_len = 0;
/* Check that the first element is valid. */
list = gcry_sexp_find_token (key, "public-key", 0);
if (!list)
list = gcry_sexp_find_token (key, "private-key", 0);
if (!list)
list = gcry_sexp_find_token (key, "protected-private-key", 0);
if (!list)
list = gcry_sexp_find_token (key, "shadowed-private-key", 0);
if (!list)
{
err = gpg_err_make (default_errsource, GPG_ERR_UNKNOWN_SEXP);
goto leave;
}
l2 = gcry_sexp_cadr (list);
gcry_sexp_release (list);
list = l2;
l2 = NULL;
name = gcry_sexp_nth_string (list, 0);
if (!name)
{
err = gpg_err_make (default_errsource, GPG_ERR_INV_SEXP);
goto leave;
}
err = gcry_md_open (&md, algo, 0);
if (err)
goto leave;
switch (gcry_pk_map_name (name))
{
case GCRY_PK_RSA:
elems = "en";
gcry_md_write (md, "\0\0\0\x07ssh-rsa", 11);
break;
case GCRY_PK_DSA:
elems = "pqgy";
gcry_md_write (md, "\0\0\0\x07ssh-dss", 11);
break;
case GCRY_PK_ECC:
if (is_eddsa (list))
{
elems = "q";
blobmode = 1;
/* For now there is just one curve, thus no need to switch
on it. */
gcry_md_write (md, "\0\0\0\x0b" "ssh-ed25519", 15);
}
else
{
/* We only support the 3 standard curves for now. It is
just a quick hack. */
elems = "q";
gcry_md_write (md, "\0\0\0\x13" "ecdsa-sha2-nistp", 20);
l2 = gcry_sexp_find_token (list, "curve", 0);
if (!l2)
elems = "";
else
{
gcry_free (name);
name = gcry_sexp_nth_string (l2, 1);
gcry_sexp_release (l2);
l2 = NULL;
if (!name)
elems = "";
else if (!strcmp (name, "NIST P-256")||!strcmp (name, "nistp256"))
gcry_md_write (md, "256\0\0\0\x08nistp256", 15);
else if (!strcmp (name, "NIST P-384")||!strcmp (name, "nistp384"))
gcry_md_write (md, "384\0\0\0\x08nistp384", 15);
else if (!strcmp (name, "NIST P-521")||!strcmp (name, "nistp521"))
gcry_md_write (md, "521\0\0\0\x08nistp521", 15);
else
elems = "";
}
if (!*elems)
err = gpg_err_make (default_errsource, GPG_ERR_UNKNOWN_CURVE);
}
break;
default:
elems = "";
err = gpg_err_make (default_errsource, GPG_ERR_PUBKEY_ALGO);
break;
}
if (err)
goto leave;
for (idx = 0, s = elems; *s; s++, idx++)
{
l2 = gcry_sexp_find_token (list, s, 1);
if (!l2)
{
err = gpg_err_make (default_errsource, GPG_ERR_INV_SEXP);
goto leave;
}
if (blobmode)
{
const char *blob;
size_t bloblen;
unsigned char lenbuf[4];
blob = gcry_sexp_nth_data (l2, 1, &bloblen);
if (!blob)
{
err = gpg_err_make (default_errsource, GPG_ERR_INV_SEXP);
goto leave;
}
blob++;
bloblen--;
lenbuf[0] = bloblen >> 24;
lenbuf[1] = bloblen >> 16;
lenbuf[2] = bloblen >> 8;
lenbuf[3] = bloblen;
gcry_md_write (md, lenbuf, 4);
gcry_md_write (md, blob, bloblen);
}
else
{
gcry_mpi_t a;
unsigned char *buf;
size_t buflen;
a = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
gcry_sexp_release (l2);
l2 = NULL;
if (!a)
{
err = gpg_err_make (default_errsource, GPG_ERR_INV_SEXP);
goto leave;
}
err = gcry_mpi_aprint (GCRYMPI_FMT_SSH, &buf, &buflen, a);
gcry_mpi_release (a);
if (err)
goto leave;
gcry_md_write (md, buf, buflen);
gcry_free (buf);
}
}
